We have made a quick-release Ditch-Kit that holds two large mouth 1L water bottles. They are dry, see-through, tough as nails and perfect for storing your survival gear. Attached to a deck-mounted platform with built-in floatation, handle, reflective binding and side anchor straps to secure additional items. The whole kit can be instantly released, letting you grab it and go.
1L bottles and ditch kit in image not included.